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Allow iptable entries with trailing text (#3060)
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danielnelson authored Jul 27, 2017
1 parent 0d4c954 commit c4297f4
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Showing 2 changed files with 56 additions and 9 deletions.
35 changes: 26 additions & 9 deletions plugins/inputs/iptables/iptables.go
Original file line number Diff line number Diff line change
Expand Up @@ -95,7 +95,7 @@ const measurement = "iptables"
var errParse = errors.New("Cannot parse iptables list information")
var chainNameRe = regexp.MustCompile(`^Chain\s+(\S+)`)
var fieldsHeaderRe = regexp.MustCompile(`^\s*pkts\s+bytes\s+`)
var valuesRe = regexp.MustCompile(`^\s*([0-9]+)\s+([0-9]+)\s+.*?(/\*\s(.*)\s\*/)?$`)
var commentRe = regexp.MustCompile(`\s*/\*\s*(.+?)\s*\*/\s*`)

func (ipt *Iptables) parseAndGather(data string, acc telegraf.Accumulator) error {
lines := strings.Split(data, "\n")
Expand All @@ -110,17 +110,34 @@ func (ipt *Iptables) parseAndGather(data string, acc telegraf.Accumulator) error
return errParse
}
for _, line := range lines[2:] {
mv := valuesRe.FindAllStringSubmatch(line, -1)
// best effort : if line does not match or rule is not commented forget about it
if len(mv) == 0 || len(mv[0]) != 5 || mv[0][4] == "" {
tokens := strings.Fields(line)
if len(tokens) < 10 {
continue
}
tags := map[string]string{"table": ipt.Table, "chain": mchain[1], "ruleid": mv[0][4]}

pkts := tokens[0]
bytes := tokens[1]
end := strings.Join(tokens[9:], " ")

matches := commentRe.FindStringSubmatch(end)
if matches == nil {
continue
}

comment := matches[1]

tags := map[string]string{"table": ipt.Table, "chain": mchain[1], "ruleid": comment}
fields := make(map[string]interface{})
// since parse error is already catched by the regexp,
// we never enter ther error case here => no error check (but still need a test to cover the case)
fields["pkts"], _ = strconv.ParseUint(mv[0][1], 10, 64)
fields["bytes"], _ = strconv.ParseUint(mv[0][2], 10, 64)

var err error
fields["pkts"], err = strconv.ParseUint(pkts, 10, 64)
if err != nil {
continue
}
fields["bytes"], err = strconv.ParseUint(bytes, 10, 64)
if err != nil {
continue
}
acc.AddFields(measurement, fields, tags)
}
return nil
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30 changes: 30 additions & 0 deletions plugins/inputs/iptables/iptables_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -124,6 +124,36 @@ func TestIptables_Gather(t *testing.T) {
{map[string]interface{}{"pkts": uint64(57), "bytes": uint64(4520)}},
},
},
{ // 10 - allow trailing text
table: "mangle",
chains: []string{"SHAPER"},
values: []string{
`Chain SHAPER (policy ACCEPT 58 packets, 5096 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 1.3.5.7 0.0.0.0/0 /* test */
0 0 CLASSIFY all -- * * 1.3.5.7 0.0.0.0/0 /* test2 */ CLASSIFY set 1:4
`},
tags: []map[string]string{
map[string]string{"table": "mangle", "chain": "SHAPER", "ruleid": "test"},
map[string]string{"table": "mangle", "chain": "SHAPER", "ruleid": "test2"},
},
fields: [][]map[string]interface{}{
{map[string]interface{}{"pkts": uint64(0), "bytes": uint64(0)}},
{map[string]interface{}{"pkts": uint64(0), "bytes": uint64(0)}},
},
},
{ // 11 - invalid pkts/bytes
table: "mangle",
chains: []string{"SHAPER"},
values: []string{
`Chain SHAPER (policy ACCEPT 58 packets, 5096 bytes)
pkts bytes target prot opt in out source destination
a a ACCEPT all -- * * 1.3.5.7 0.0.0.0/0 /* test */
a a CLASSIFY all -- * * 1.3.5.7 0.0.0.0/0 /* test2 */ CLASSIFY set 1:4
`},
tags: []map[string]string{},
fields: [][]map[string]interface{}{},
},
}

for i, tt := range tests {
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